How to make a menu like this

Hi, I’m wondering if it is possible to make a menu in WordPress like this:
Link1
Link2
Link3
Link4

Just plain text, no fancy effect, no nothing.
And when people click at a link, lets say Link3, another “box” of links get added to the right, like this:
Link1 Link3-1
Link2 Link3-2
Link3 Link3-3
Link4

Can someone help me out? Thanks in advance.

Edit:
Landor.com has something similar to what I have in mind, check it out if you don’t understand what I mean.